Power supply unit



FIG. 1 is a back perspective view of a power supply unit;

FIG. 2 is a front view thereof;

FIG. 3 is a back view thereof;

FIG. 4 is a right side view thereof;

FIG. 5 is a left side view thereof;

FIG. 6 is a top view thereof; and,

FIG. 7 is a bottom view thereof.

The broken lines of the drawings depict portions of the power supply unit that form no part of the claimed design. 

CLAIM The ornamental design for a power supply unit, as shown and described. 